This invention relates to novel solid herbicidal compositions containing the herbicide N-phosphonomethylglycine (also known as glyphosate) together with a solid alkyl phenol polyoxyalkylene carboxylic acid-containing surfactant.
N-phosphonomethylglycine, as well as analogous compounds including salts, and the herbicidal properties and formulations containing them, are described in numerous patents such as U.S. Pat. No. 3,799,758. This patent describes a number of compositions containing N-phosphonomethylglycine and analogous compounds and discloses that the incorporation of a surface-active agent into such compositions "greatly enhances their efficiency".
That patent generally discloses that solid compositions of various types may be prepared, but no specific examples of solid compositions are mentioned.
Solid compositions containing N-phosphonomethylglycine, however, are mentioned in a number of references including European Patent Applications Nos. 448538 and 498145 and U.S. Pat. Nos. 4,931,080 and 5,118,338.
Copending U.S. application Ser. No. 08/90,583 (U.S. Pat. No. 5,362,705) Nadim Moucharafieh et al. discloses the preparation of dilute aqueous compositions containing from about 0.1 to about 1.5 weight percent N-phosphonomethylglycine and from about 0.1 to about 5 weight percent of an alkyl phenol polyoxyalkylene surfactant containing from about 50 to about 90 weight percent alkyl phenol polyoxyethylene carboxylic acid. The patent application mentions that one means of forming such compositions is to first prepare a concentrate containing N-phosphonomethyl-glycine or one of its more water-soluble derivatives (such as an alkali metal or amine salt) with the alkyl phenol polyoxy-alkylene surfactant and then dissolving the concentrate in water. This information represents the work of the present inventor, which is disclosed in more detail and claimed herein.